720 research outputs found
Non trivial critical exponents for finite temperature chiral transitions at fixed total fermion number
We analyze the finite temperature chiral restoration transition of the
-dimensional Gross-Neveu model for the case of a large number of
flavors and fixed total fermion number. This leads to the study of the model
with a nonzero imaginary chemical potential. In this formulation of the theory,
we have obtained that, in the transition region, the model is described by a
chiral conformal field theory where the concepts of dimensional reduction and
universality do apply due to a transmutation of statistics which makes fermions
act as if they were bosons, having zero energy. This result should be generic
for theories with dynamical symmetry breaking, such as Quantum Chromodynamics.Comment: 14 pages Latex, no figures, final version to be published in Phys.
Lett.
One-loop dimensional reduction of the linear sigma model
We perform the dimensional reduction of the linear model at one-loop
level. The effective potential of the reduced theory obtained from the
integration over the nonzero Matsubara frequencies is exhibited. Thermal mass
and coupling constant renormalization constants are given, as well as the
thermal renormalization group equation which controls the dependence of the
counterterms on the temperature. We also recover, for the reduced theory, the
vacuum unstability of the model for large N.Comment: 19 pages, Latex, no figures, to be submitted to Physica
Cardiovascular and respiratory responses to microinjection of L-glutamate into the caudal pressor area in conscious and anesthetized rats
The role of the caudal pressor area (CPA) in the maintenance of vasomotor tonus in anesthetized and decerebrate animals has been clearly established. In conscious animals, however, the participation of CPA in the cardiovascular control remains to be fully elucidated. In the present study, unilateral L-glutamate (L-Glu) (10 and/or 20 nmol/70 nl) microinjection into CPA, in conscious male Wistar rats (250-280 g) caused a significant increase in mean arterial blood pressure (MAP; control: 112 ± 1.9 mmHg; after 20 nmol L-Glu: 139 ± 4.5 mmHg, N = 12, P<0.05) and respiratory rate (control: 81 ± 3.5 breaths/min; after 10 nmol L-Glu: 92 ± 3 breaths/min, P<0.05; after 20 nmol L-Glu: 104 ± 5 breaths/min, N = 6, P<0.05). The subsequent anesthesia with urethane caused a significant increase in basal respiratory frequency (conscious: 81 ± 3.5 breaths/min; under urethane: 107 ± 1.3 breaths/min, N = 6, P<0.05). Anesthesia also significantly attenuated L-Glu-evoked pressor (conscious: deltaMAP = +27 mmHg; anesthetized: deltaMAP = +18 mmHg, P<0.05) and respiratory responses. These results suggest that glutamatergic receptors in the CPA are involved in cardiovascular and respiratory modulation in conscious rats.Universidade Federal do Espírito Santo Centro Biomédico Departamento de Ciências FisiológicasFAESA Faculdade de Saúde de VitóriaUniversidade Federal de São Paulo (UNIFESP) Disciplina de Fisiologia CardiovascularUNIFESP, Disciplina de Fisiologia CardiovascularSciEL
Genetic diversity among air yam (dioscorea bulbifera) varieties based on single sequence repeat markers
Dioscorea is the largest genus in the Dioscoreaceae family, and includes a number of economically important species including the air yam, D. bulbifera L. This study aimed to develop new single sequence repeat primers and characterize the genetic diversity of local varieties that originated in several municipalities of Brazil. We developed an enriched genomic library for D. bulbifera resulting in seven primers, six of which were polymorphic, and added four polymorphic loci developed for other Dioscorea species. This resulted in 10 polymorphic primers to evaluate 42 air yam accessions. Thirty-three alleles (bands) were found, with an average of 3.3 alleles per locus. The discrimination power ranged from 0.113 to 0.834, with an average of 0.595. Both principal coordinate and cluster analyses (using the Jaccard Index) failed to clearly separate the accessions according to their origins. However, the 13 accessions from Conceição dos Ouros, Minas Gerais State were clustered above zero on the principal coordinate 2 axis, and were also clustered into one subgroup in the cluster analysis. Accessions from Ubatuba, São Paulo State were clustered below zero on the same principal coordinate 2 axis, except for one accession, although they were scattered in several subgroups in the cluster analysis. Therefore, we found little spatial structure in the accessions, although those from Conceição dos Ouros and Ubatuba exhibited some spatial structure, and that there is a considerable level of genetic diversity in D. bulbifera maintained by traditional farmers in Brazil152CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPnão tem2007/04805-
From Megawatts to Kilowatts: A Review of Small Wind Turbine Applications, Lessons From The US to Brazil
Increased use of fossil fuels has contributed to global warming due to greenhouse gas emissions, which has led countries to implement policies that favor the gradual replacement of their use with renewable energy sources. Wind expansion in Brazil is a success story, but its adherence to distributed generation is still a big challenge. In this context, the authors of this paper argue that the development of robust and viable distributed power grids will also depend in the future on improving small wind generation as an important alternative to the diversity of decentralized power grids. In this study, the authors present an overview of the small-sized Aeolic (or wind) energy market in Brazil, with the objective to support the debate regarding its expansion. Promoting the small wind market in Brazil is still a big challenge, but lessons can be learned from the United States. In this context, the article uses the United States learning curve, analyzing barriers that were found, as well as public policies implemented to overcome them. The lessons learned in the American market may guide public policies aimed at fostering this technology in Brazil. If technological improvements, certification and introduction of financial incentives were implemented in Brazil, the small wind industry chain could grow substantially, building a trajectory to promote the low carbon economy
PREVISÃO DE ESCORREGAMENTOS TRANSLACIONAIS RASOS E ÁREA DE DUTOS: ESTUDO DE CASO DO MACIÇO DO TINGUÁ NA RESERVA BIOLÓGICA FEDERAL DO TINGUÁ (RJ).
Os movimentos de massa são grandes causadores de prejuízos financeiros, podendo danificar redes de infraestrutura como oleodutos e gasodutos. O objetivo desse trabalho é realizar uma análise das condições de estabilidade das encostas do Maciço do Tinguá, na Reserva Biológica Federal do Tinguá (RJ), por onde passam oleodutos e gasodutos. Utilizou-se um modelo matemático de base física e os resultados propiciaram uma análise preliminar da susceptibilidade a escorregamentos translacionais na área
Estruturas De Poder Nas Redes De Financiamento Político Nas Eleições De 2010 No Brasil
This article analyses 299,968 relationships established between 251,665 actors (donors and/or recipients) of financial legal resources declared by candidates and parties in all positions at stake in the 2010 elections in Brazil. Data from the Tribunal Superior Eleitoral (Superior Electoral Court) was used, together with the methodology of social network analysis and complementary statistical procedures, to explore the topology of the subnets (components) and of the calculations of the centrality of the actors - candidates, party agents and private funders. The results show the high connectivity and asymmetry of the campaign finance network in Brazil and they expose that the positioning of the actors in the network layers is crucial to the performances of both the candidates and the funders, revealing, in an unprecedented way, the existence of a political elite within the Brazilian electoral system.221285
Dimensional reduction of the chiral-continous Gross-Neveu model
We study the finite-temperature phase transition of the generalized
Gross-Neveu model with continous chiral symmetry in euclidean
dimensions. The critical exponents are computed to the leading order in the
expansion at both zero and finite temperatures. A dimensionally reduced
theory is obtained after the introduction of thermal counterterms necessary to
cancel thermal divergences that arise in the limit of high temperature.
Although at zero temperature we have an infinitely and continously degenerate
vacuum state, we show that at finite temperature this degeneracy is discrete
and, depending on the values of the bare parameters, we may have either total
or partial restoration of symmetry. Finally we determine the universality class
of the reduced theory by a simple analysis of the infrared structure of
thermodynamic quantities computed using the reduced action as starting point.Comment: Latex, 25 pages, 4 eps fig., uses epsf.sty and epsf.te
Uso De Práticas Integrativas E Complementares Por Doulas Em Maternidades De Fortaleza (ce) E Campinas (sp)
This study aimed to analyze the Integrative and Complementary Practices (ICP) applied by doulas in the cities of Fortaleza (CE) and Campinas (SP). This is a qualitative study encompassing fifteen doulas: nine from Fortaleza and six from Campinas. The data were collected in the second half of 2010 by conducting semi-structured and pre-organized interviews following the procedures of thematic content analysis. The interpretations of the results were based on the idea that institutionalization of knowledge and practices happen through the conformation of nuclei and fields. The nucleus demarcates the identity of an area of knowledge and the professionals’ practices, and the field demarcates the blurred limits among disciplines that can be submitted to conflicts. We observed that the support offered by doulas permeates a variety of practices framed in traditional medicine as well as in complementary and alternative medicine. ICP was associated with decreases in length of labor, superior pain management, ability of making decision and empowering of women. It is understood that the range of activities offered by doulas and the use of ICP converge to the uniqueness, respect and autonomy of women. Furthermore, it proposes a new model of awareness and practices centered on the importance of the natural process of childbirth. © 2016, UNIV SAOPAULO. All rights reserved.25110812
Estimativa da área foliar do pepino em ambiente protegido por medidas lineares sob salinidade e enxertia
The measurement of leaf area by linear parameters is a useful tool when plants cannot be destroyed for direct measurement. The objectives of this study were to establish equations to estimate the leaf area of greenhouse-cucumber and to evaluate the effects of salinity and grafting on this estimative. Non-grafted cucumber seedlings, cv. 'Hokushin', were transplanted in a greenhouse and were irrigated with water of different salinities (1.0, 3.2 and 5.0 dS m-1). In the second growing period, the same cultivar was grafted on Cucurbita spp. and the plants were irrigated with water of 1.4, 3.0 and 5.3 dS m-1. Leaves of different sizes were collected from both experiments and leaf area was determined by an integrating area meter. Leaf length (L) and width (W) were also recorded. An equation for estimating the leaf area from L and W was developed for a given salinity level or grafting condition and estimated well the area of leaves collected in the other treatments. The leaf area (LA) of cucumber 'Hokushin' could be estimated using the equation LA = 0.88LW - 4.27, for any grafting and salinity conditions.A determinação da área foliar por medidas lineares é uma ferramenta útil quando as plantas não podem ser destruídas para que a medição direta seja realizada. Os objetivos desse trabalho foram definir equações para a estimativa da área foliar do pepino em ambiente protegido e avaliar os efeitos da salinidade e da a enxertia nessa estimativa. Mudas de pepino, cv. 'Hokushin', não enxertadas, foram transplantadas em um ambiente protegido e irrigadas com água de diferentes salinidades (1,0, 3,2 e 5,0 dS m-1). No segundo período de cultivo, a mesma cultivar foi enxertada sobre Cucurbita spp., sendo as plantas irrigadas com água de 1,4, 3,0 e 5,3 dS m-1. Foram coletadas folhas de diferentes tamanhos dos dois cultivos e dos três tratamentos e a área foliar foi determinada por um medidor de área foliar. O comprimento (C) e a largura (L) da folha também foram registrados. Desenvolveram-se equações pelas quais a área foliar pôde ser estimada a partir de medidas de C e L. A equação desenvolvida para um dado nível de salinidade ou condição de enxertia estimou bem a área das folhas coletadas nos demais tratamentos. A área foliar (AF) do pepino 'Hokushin' pode ser estimada pela função AF = 0,88CL - 4,27, para qualquer condição de enxertia e salinidade
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